The objective of this proposal is to study the expression of kinetoplast DNA (kDNA) in Leishmania chagasi. Initially, kDNA from L. chagasi will be cloned in E. coli plasmid vectors and both the mini-circle and maxi-circle DNA will be characterized with respect tot their coding properties and transcriptional variations in the infective and non-infective cells. The restriction maps of both these DNA species will be established using classical methods. The transcription maps will be constructed using total cellular RNAs and also using DNA probes for known mitochondrial gene products. Both in vivo and in vitro translation systems will be used to identify and compare the kinetoplast geneome coded proteins under different physiological conditions of infectivity. These studies may lead to the understanding of kDNA structure, function, and organization and also its possible role in the pathogenesis.